1. Field of the Invention
The embodiments disclosed herein relate to a matrix converter and a control method therefor.
2. Description of the Related Art
A matrix converter includes a plurality of bidirectional switches for connecting an AC power source and a load, and controls those bidirectional switches for direct switching of phase voltages of the AC power source so as to output an arbitrary voltage and frequency to the load.
In the matrix converter, the phases of the AC power source to be connected to the load are switched by the bidirectional switches by controlling each of a plurality of unidirectional switches constructing the bidirectional switch to be turned on and off separately in a predetermined order (this series of switching operation is referred to as a commutation operation). By this commutation operation, a short circuit between the phases of the AC power source, an open output phase of the matrix converter, or the like can be prevented (see, for example, International Patent W02008/108147A).
However, a parasitic capacitance exists as a capacitance between an input terminal and an output terminal of the unidirectional switches constructing the bidirectional switch (when a snubber capacitor is connected between the input and output terminals, the capacitance between the input and output terminals is the parasitic capacitance plus a capacitance of the snubber capacitor). This parasitic capacitance causes distortion of output voltage or output current, and hence drive performance of the matrix converter may be deteriorated.
One aspect of the embodiment is made in view of the above description, and it is an object thereof to provide a matrix converter and a control method therefor, which can reduce the distortion of output voltage or output current due to the parasitic capacitance.